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yeasts, the strain with the optimum pH closest to that of wine was AL 41. The optimum temperatures were foundto be about 62 and 20-25°C for βG from Aspergillus niger and yeasts, respectively. Under these last conditions,which may be considered the temperature of potential use of the enzymes in oenology, mould βG relative activitywas found to be 40-50%. Enzyme stability in wine model solution (at 20°C) was 12 days for mould activityand at least 35-45 for that from yeasts. Finally, the V max value for βG from Aspergillus niger was 4.85 U mg -l ofprotein and ranged from 1.71-6.98 for the yeasts, while the K m values were 0.63 mM and 0.55-2.55 for βG frommould and yeasts, respectively. The commercial preparation enzyme would be useful in late alcoholic fermentation,whilst some yeast strains (AL 112 and AL 41) could be directly added during fermentation in order to enhancewine aroma.2) Barbagallo R.N., Palmeri R., Fabiano S., Rapisarda P., Spagna G. (2007). Characteristic of β-glucosidase from Sicilian blood oranges in relation to anthocyanin degradation. Enzyme andMicrobial Technology, 41: 570-575.Anthocyanin content in Sicilian sweet orange [Citrus sinensis (L) Osbeck] varieties known as blood oranges(Tarocco, Moro e Sanguinello) undergoes changes during the ripening process. Concentration increases duringripening, reaching a maximum in the fully ripe fruit. At latter stage of maturity, a decrease of these pigments isobserved. This study aims to evaluate β-D-glucosidase activity ( G, EC 3.2.1.21) in Tarocco variety, the mostcommon Sicilian blood orange, and to determine the main physicochemical and kinetic properties of this enzymein order to underline its role on anthocyanins degradation during ripening. The enzymatic extract was assayed onboth anthocyanins extract from Tarocco juice and a synthetic substrate (p-nitrophenyl-βD-glucopiranoside,pNPG). It was observed a 400 times higher specificity of the synthetic substrate than the natural substrate. Kineticstudies and physicochemical characterization of βG such as V max and K m (V max 2.1 10 -2 and K m 2.67 10 -4using pNPG as substrate; V max 3.3 10 -3 and K m 2.1 10 -1 using natural substrate), optimum conditions of pH (4.5)and temperature (60°C), fructose and glucose inhibition (competitive inhibition by glucose) and thermal stability(decimal reduction time 3 min at 75 °C and decimal reduction temperature 9.5 °C) were also performed. β-Dglucosidaseactivity seems involved on anthocyanins degradation during final ripening stage of fruit.3) Barbagallo R.N., Chisari M., Branca F., Spagna G. (2007). Pectin methylesterase, polyphenoloxidase and physicochemical properties of typical long-storage Cherry tomatoes cultivatedunder water stress regime. Journal of the Science of Food and Agriculture, 88: 389-396.The selection of cherry tomato genotypes with extended shelf-life and resistant to water stress is animportant aspect of Sicilian agriculture. The aim of the present study was to evaluate the effects of wateringregime on the expression of enzymatic activities, pectin methylesterase (PME, EC 3.1.1.11) andpolyphenol oxidase (PPO, EC 1.14.18.1) and the physicochemical properties of typical long-storagecherry tomatoes in order to propose a solution strategy suitable for Sicilian cultivation. PPO activityseemed to be related to the watering regime employed, showing amaximum under normal wateringconditions. PME activity also decreased greatly with increasing water stress (loss of activity rangingfrom 22.31 to 82.01%). Water stress induced an increase in titratable acidity (up to 64.3% in cultivar‘Rosso’) and, above all, in dry matter and total soluble solids (increases ranging from 19.41 to 47.83%and from 5.60 to 29.03% respectively). Possible solution strategies for cultivation of tomato genotypeswith extended shelf-life are (a) selecting the local type that presents the lowest levels of PME and PPO(‘Pizzutello’) or (b) modifying the watering regime in order to induce commercial cultivars employedin intensive cultivation (e.g. ‘Naomi’) to better protect themselves from degradative enzymatic activities.It appears that the adoption of high watering levels, leading to a more marked expression of degradativeenzymatic activities, could result in cherry tomatoes with a high susceptibility to undesirablebrowning and softening reactions.SISTAL - SOCIETA’ ITALIANA DI SCIENZE E TECNOLOGIE ALIMENTARIDipartimento di Scienze e Tecnologie Agroalimentari, Università degli Studi della TusciaVia San Camillo de Lellis, 01100 ViterboTel.: 0761- 35 74 94/7 , Fax: 0761- 35 74 98, e-mail: mmoresi@unitus.it71